Carrier wave signaling system



A ril 18, 1933. J. w. SCHMIED 1,904,544

CARRIER WAVE SIGNALING SYSTEM Filed Jan. 31, 1924 8 Sheets-Sheet l l g: a 0

8 CHKZAGO 2 I NEWYORK 0 7 5 57 SAN FRANCISCO WASH'NGTON NEW omems 95 FILTER mmm. FILTER U0 CHICAGO. A99 205 50m FILTERS-b HLTER MODUL H ER 2 //7 yen/0r:

Jages l/l/ Schm/ed fiy fil April 1933; J. w. SCHMIED 1,904,544

CARRIER WAVE SIGNALING SYSTEM Filed Jan. 51, 1924 8 Sheets-Sheet 2 AMPLIFIERS FILTERS LATORS //7 en/0r: James W Sch/med 4 19 y W April 18, 1933.

Filed Jan. 31, 1924 8 Sheets-Sheet 3 J DETECTOR 6%KC 44 FILTER AMPLF- AMPLIFIER FILTER DETECTOR RADIO CONTROL AMPLIFIER MODUILATOR AMPLIFIER MODULATOR 53'5KC 4 7 FILTER AMPLIFIER //7 en/0r:

Jam 65 April 18, 1933.

CARRIER WAVE SIGNALING SYSTEM J. W. SCHMIED Filed Jan. 51, 24

AMPLIFIER FILTER 20KB H GI 8 Sheets-Sheet 4 MODULATORS AMPLIHER AMPLIFIER HLTER AMPLIFIER 2 DETECTOR FILTER DETECTORS I20 KC I //7 wen/0r: James W Sch/Wed April 1933- J. w. SCHMIED 1,904,544

CARRIER WAVE SIGNALING SYSTEM Filed Jan. 31, 1924 8 Sheets-Sheet 7 IOZOKC (s l l I AMPLIFIER MGDULATHR mm w AM DETECTOR AMPLF. FILTER 40KB "SI FILTER In yen/0r: VV. chm/ed pril 18. 1933. J. w. SCHMIED 1,904,544

CARRIER WAVE SIGNALING SYSTEM Filed Jan. 51, 1924 8 Sheets-Sheet 8 1' KC HLTERand |o2oKc+s, DETECTOR AMPUHER 05mm 4 05 L #6 /77 NHUAL /75 7 lflfi lunk MODULATOR FILTER MODULATOR FILTER T g M0 0/ //7 ven/or: James 1 14 Sch/Wed by. My

Patented Apr. 18, 1933 JAMEs W. scEivrIEn, 0E WEs'roEANGE, NEW JERsEY, ASSIGNOR 'ro WESTERN ELEcTRIo if COMPANY, INCORPORATED, OF NEW YORK, N. Y.,-AcoEPoEATIoN. or NEWyoEK V .cAEEiER AVE sIGNALINe SYSTEM 1 Application med January 31,1924. serial 0. 689,627.11 7

This invention-relates to carrier signalingand more particularly to a'method'of and means for controlling the signaling :frequencies used by the different stations 'included in an organization comprising anynumberof carrier systems. I I

In a carrier signa lingorgamzation com prlsmg a number of systems which are as.

sociated and are to be independently operorder to avoid interference, that there should be maintained a definite frequency spacing betweenall the signal" frequencies used in the difi'erent channels. 1 This invention provides an arrangement'in which all frequenciesusedin a number of associated carrier systems, some of which may use wire guided waves and others may utilize free unguided'waves, are controlled from a single control; or =Inaster station,

' whereby there is prevented any relative shift in the frequency band assigned tdthe dif-x ferent systems and also any relativechange in the frequencies used for the different channels of the several systems. I

In accordance with the present invention this result may be secured by'generating at a master station and transmitting to the terminal stations of the several systems fundamental or. base frequency from "which is derived all the frequencies used on the different systems. More specifically considered the fundamental or base frequency:

is supplied at the terminal station of each system to a harmonic generator from-which different harmonically related frequencies are selected and used for two-Way communications over one or more channels between the stations of thesystem.

The primary object of this'inventio is to controlthe frequency relation of the wavesusedlin a carrier organization comprising plurality of t x A featureof the invention is an arrange ment for definitely=-fixing relatively to each othergthe frequency bandsv used in af'plumayor associatedcarrier systems.

Another feature relates to the provision of a single control meanswhereby a plll rality of carrier systems each having one or more channels may be. combined to constitutea unitary'organization in which a fixed relation for all the frequencies used in the difierent'systems may be maintained.

Still another feature is an organization in which-carrier communications may. be repeated from Wire lines'to radio systems. A still further feature relates toasingle control means. fo'r'all the carrier-[frequencies used in-an organization comprising wire ear:

rier systems andradio systems each having one or morechannels'. j n Ifthe same carrier frequencies-amused for a plurality of simultaneous 'communica-1 tions in high frequency systems wherein portions of the energy of the carrier'wa ve of one of the channels is effective upon "the receiver of another; channehand fthe Jfr'equencies are slightly out of synchronism a beat 'noteresults which in general isIaudible; This beat note phenomenon is readily .ob'- served in connection" "with. present broadcasting wherein two stations, perhaps many hundreds of miles apart, are using what is,

within the'limits of measurements, the same wave length, the same frequency. Asa mat ter of fact thesear'e almost always of slight ly different frequency and receiving detectors produce a very troublesome,.often audible, sometimes inaudible, sometimes rapidly varying beat note. Use of the'well know method of carrier suppressionmay oftenb advantageous in reducing, difliculties of" this sort'but in the-present stateof the art 100% suppression of the unmodul'ated carrier "component of a radiated wave is diflicultYto" achieve. The present invention-maybeap plied with or without carrier suppression and has for one object to provide anddocs provide a remedy for heat not ?;tmub1'es by insuring throughout a region of any d; 100

sential features of this invention reference should be made to the following description of certain embodiments thereof read in connection with the attached drawings of which Fig. 1 is a schematic diagramillustrating an organization of linewire, ship-to-shore, and ship-to-ship channels to which the invention may be applied.

Fig. 2 illustrates a master or control terminal station for.- a wire. carrier system.

Fig. 3 shows one type of terminal station for. a wire carrier and radio organization.

Fig. 4 illustrates a radio terminal station for use with the terminal station shown in Fig. 3. n

' ig. 5 shows a wire carrier-radio terminal station, which is adapted for application as a shore station of a ship-to-shore system.

Fig. 6 illustrates a terminal radio station,

such asa ship station or isolated land sta-.

tion.

Fig. 6 A illustrates an arrangement which may be used in place of the elements shown at the left of the section line AA Fig. 7 illustrates a radio terminal station I which may be used in this organization in place of that shown in Fig. 4.

Fig. 8 shows a radio terminal station. I

which may be used with the station shown in Fig. 7. d

Fig. 9 shows an organization involving the invention in which messages may be simultaneously transmitted from a plurality of radio terminal stations either on identical Wave lengths, as shown, oron different but definitely related wave length, and

Fig. 10 illustrates a radio terminal station for use with the interconnecting channel shown in Fig. 7.

Merely for the purpose of giving a concrete example of an organization in which the invention may be used the schematic diagram shown in Fig. 1 illustrates a carrier network including channels connecting certain places in the northern part of the western hemisphere.

Figure 1 Referring to Fig. 1 there is shown a master control station 1, marked Chicago,

connected by wire lines with distant terminal stations 2 to 10 inclusive, certain of which are marked New York, Washington, New Orleans, San Francisco. Stations 2, 3, 5, 7 and 10 are shown as wire terminal stations having radio terminal stations associated with them and remote radio stations 11 adapted to cooperate with the radio stations of 2 and 5 are also shown. The other stations, viz. l, 4, 6, 8 and 9, are shown as terminal stations for wire systems, but they may also be associated with radio systems. A fundamental feature of the invention is that all carrier frequencies throughout the system are controlled by a source located at any particular station which is selected as the master control station.

Fig. 2 illustrates a station adapted to serve as a master control station and as a terminal station which is typical of those used in multiplex wire carrier systems.

Figure 2 The station shown in Fig. 2, adapted for carrier telephony is provided with a source 12, which may be a machine, a space discharge oscillator or other suitable source, for producing a fundamental or control frequency of, for example, three and one third kilocycles, which is supplied to a harmonic generator 13. n n

. The source 12 is maintained at, a very constant frequency either by skilled attendants or by means of automatic regulating means now well known to those skilled in the art.

The output circuit of thegenerator 13 includes devices 14 to 22, which may be tuned circuits or filters, each of which is selective of one of the harmonic frequency components present in the output circuit of the generator.

The device 18 is frequency which, after being amplified by the device 23, is transmitted through a second selective device 24 to the line 25. This line is connected to the remote terminal of a two-way carrier system and to other systems included in the carrier network.

Devices 14: to 17 inclusive, may be respectively selective of the second, third, fourth and fifth multiples of the base frequency. These multiple frequency waves are used as outgoing carrier waves for the different channels. Devices 19 to 22 inclusive are respectivelyselective of the seventh,'eighth, ninth and tenth multiples of the base frequency. These are used to combine with the respective incoming modulated carrier waves to effect detection.

The operation of the terminal apparatus for each of the channels of each of the wire carrier systems is identical. The following description of the operation of the apparatus for the first channel at the master conadapted to select the base trolterminal station will therefore serve to set forth the operation of the terminalapparatus for all channels of the several systems'included in the organization.

A line 26, which may be a telephone line connected directlyrwith a local subscriber or through a. local exchange, isadapted to transmit low frequency current to the terminal station and is connected: to one pair of terminals of the line windings'of a hybrid coil, the opposite terminals of which are connected to a balancing network N. The center taps of the hybrid coil are connected to a local transmitting circuit TC, and the third winding of the hybrid coil is connected to a local receiving circuit RC.

The second multiple of the base frequency, i. e. 6% kilocycles, which is used as'an outgoing carrier current for the first channel is amplified by the device 27' and supplied to the modulator 28. Incoming speech current of frequency S is transmitted over the line 26 and circuit TO to the modulator 28. The carrier and speech currents are combined in the device 28 to produce a modulated carrier current which is amplified by the device 29 and, transmitted through the filter 30 and conjugate coupling to the line 25. The line 25 is associated with the carrier channel circuits CTC and CEO by a conjugate connection similar to that described above for the line 26'. The filter 30 is designed to select the upper side band of thecarrier, i. e. 6 kilocycles-l-S, (S being the symbol commonly used to designate the frequencies of speech waves) and to suppress both the carrier component and lower side band,- whereby only the upper side band is transmitted over the line 25.

The incoming carrier frequency for the first channel is the tenth harmonic, i. e. 33% kilocycles, and the lower side band only is used. (The term harmonic is used herein in the sense of multiple frequency, thus tenth harmonic means a frequency of ten times the base frequency.) Thus the frequency of the incoming modulatedcarrier current is 33 kilocycles-S. i

The modulated current received over the line 25 istransmitted through the filter 31 to the demodulator or detector 32 where it is combined with the current of 33% kilocycles supplied through the filter 22 and amplifier 33 to produce the speech currents which are transmitted over-the circuit RG and line 26 to the subscriber.

systems radiating from this station will be provided with terminal apparatus similar to that described above. As is indicated by the taps associated with the output sides The output of the detector 32 should be connected rents of diiferentfrequencies may be supof:the filters 14. to 22 inclusive, carriericur pliedto the diflerent'channels of the several wires systems emanating from the control station. Moreover, the equipment of each of the other stations for the wires systems, the generator 12 being omitted, will beidentical with that shown in Fig. 2.- It is contemplated that the base frequency-of kilocycles will be generally: transmitted so as to be available at all carrier terminals.

Figm'e V Fig. 3 illustrates what may be called a combined station. That is, a station equip ped with wire carrier terminal apparatus, through .line carrier repeating apparatus, and means whereby a control frequency may be supplied toaradiosystem. -z-It is therevices 34, 35, 36,37 and 38 which respectively select the different channel frequencies incoming over the line-25. Figs. 2 and 3 therefore illustrate the cooperating terminals of a four-channel carrier multiplex system.

GTC includes the devices 39, 40, 41 and 42 which respectively selectthe modulated carrier waves or, more specifically the side bands, suppliedthrough the different channelsto the line 25. p

The fundamental or control frequency is selected by the filter 38 which has its output side connected to a harmonic generator HG.

The output circuit of the generator HG is completed by a switch 43. With switch Returning to Fig. 3, transmitting circuit 43 in one position the output circuit of'the' generator is closed to include selective devices 44, 45, 46 and 47. Oscillations of different harmonic frequencies. may be supplied through devices 44 and 45 respectively, to the detector 48 and 49. Devices 46 and 47 respectively, supplycarrier currents of harmonic frequencies to the modulators 50 and 51. When the switch 43 occupies its other position, a filter 52, inaddition to fil ters 44 to 47 ,is includedin the output circuit of the generator HG.: .Filter 52 selects a harmonic frequency which is amplified by the device 53, again selected by the filter 54 and supplied to a radio control line-55. i

The device 52 selects 'a'wave of the frequency of 20 kilocycles which, "it is important to note, is not used in a signaling channel of the carrier system.

The first and third channels at this station: I

are provided with terminal apparatus, similar to that shown in Fig. 2, for connecting the carrier line 25'to lowfrequency ortele phone lines. The first channel is shown conjugately connected to a telephone line 26. Similarly the terminal apparatus for the third channel will be conjugately associated with a second telephone line, but, for thesake of clarity the connecting means has been omitted.

The second and fourth channels are adapted to operate as repeating circuits through which the signal modulated waves incoming over the line 25 may be transmitted over a second carrier line 56 conjugately associated with the repeating apparatus.

Assuming that the station shown in Fi 3 is New York, the switch 43 is in its lower position, the first and third channels are connected through a telephone exchange to different subscribers and that channels 2 and 4 are connected for repeating over line 56 to station 10, Fig. l.

Signal modulated waves, or more precisely side bands of, for example, 6% KC-FS, and 13% KGl-S respectively, received over channels 1 and 3 of line 25 from a dis tant station will be combined with local oscillations of 6 KC and 13 KO, respec tively, in the detectors 48 and 49'and the resultant speech currents will be transmitted over different telephone lines tolocal subscribers. The output circuits of the detectors 48 and 49 should each be provided with selective devices for the speech currents. Carrier modulated waves respectively received over channels 2 and 4 of line 25 will be selected by devices 85 and 37, amplified, again selected and transmitted over line to a distant station, for example 10, Fig. 1, where they maybe detected and the signal currents transmitted to local subscribers, or as will appear later, the carrier modulated waves may be used to modulate a radio carrier wave for transmission to a distant radio station.

By throwing the switch 43 to its upper position the filter 52 will be included in the output circuit of the generator HG and, in addition to the functions just described 2". r channels 1 to 4, there is provided a fifth channel through which a wave of a frequency harmonically related to the fundamental frequency may be supplied to the radio control circuit 55. be a channel on any convenient low frequency telephone. line if a separate line is not available.

Instead of transmitting the speech currents to a local subscriber, the arrangement shown in-Fig. 3 may be associated with a radio system. The New York terminal station may be connected through a radio terminal station 57, Fig. 1, for communication with distant radio stations 11, herein shown, by way of example, as ships at sea. Thus at terminal station 57 the speech currents transmitted over the telephone lines, for exhe line may ample 26, etc., or the side bands transmitted over the line 56, may be used to modulate carrier waves of different radio frequencies derived from the 20 KC radio control wave transmitted over the line 55 or over one of the carrier lines.

A terminal station for producing speech modulated radio carrier waves is shown in Fig. 4 and one ,in which a carrier wave modulated by speech is used to modulate a radio frequency wave is shown in Fig. 5.

Figure Referring now to Fig. 4 there is shown a multiplex radio system. The complete cir cuit arrangement for only one channel is illustrated, but similar connections will be used for the other channels.

The low frequency line 58, which may extend from a local station or may be one of the telephone lines extending from the station shown in Fig. 3, is conjugately connected to transmitting and receiving circuits TC and RC respectively. The circuit TC is connected through a filter 59 and amplifier 60 to a modulating device 61.

The radio control frequency transmitted over the control line 55 is supplied to the harmonic generator HG and through a transformer 62, to antenna 63 from which it i continuously radiated. The radio. control frequency, as indicated on the drawings is 20 kilocycles. V

The out-put circuit of the harmonic generator HG is provided with selective devices or filters 64 to 71. Each of these dcvices is adapted to sharply select and freely transmit one of the frequencies, harmonically related to the radio control frequency, which are produced by the generator HG. If necessary separate amplifiers are asso ciated with each of the devices 64 to 71.

Although a multiplex radio system is shown, the complete circuits for one channel only are illustrated. Since all of the channels operate in. the same manner, except that differentfrequencies are used. in each channel, it is believed that a description of the operation of one channel will suflice to illustrate the operation of the system.

The eighth harmonic or wave of 160 kilocycles frequency is supplied to the device 61 through a filter 64. Thelow frequency currents and radio carrier wave are combined in the device '61 to produce a modulated carrier wave. The device 61 comprises a combined modulator and filter as is well known in the art, whereby the unmodulated carrier component and one side frequency component are suppressed and the other side frequency component after being. amplified by the device 72 is delivered to and radiated from the antenna 7 3. As indicated,'the upper side band, i. e., 160 kilocycles+S is transmitted. The incoming carrier wave for this channel is herein indicated as the lower side band derived from a carrier of 180 kilocycles, andhence has a frequency of 180 kilocycles S where S i ndicates the frequency of the low frequency modulating current.

The received wave of 180 kilocycles-S incident upon the antenna 74: is transmitted to the detector 7 5 where it is combined with oscillations of lfiO kilocycles supplied by the harmonic generator HG through the filter 71. A carrier modulated wave of 20 kilocycles-n8 is delivered by the detector 75, which may include separate amplifiers, through the filter 76 to a second detector 77. Carrier oscillations of 20 kilocycles are suplied by the transformer 62 to the detector 7 7 The output of the'detector 77 contains a current component of modulating frequency S which, after being amplified by the device 78, is transmitted through the filter 79 selective of the speech frequency current circuit RC and conjugate connection to the line 58. I a

With the arrangement described above, two-way communication, under the control of the master control station may be maintained'with aremote radio station or stations. In a similar manner anynumber of communications, limited only by practical considerations, may be held between the radio'terminal station and remote radio stations. I v

The radio system-shown in Fig. 5 may be associated with a line carrier system to provide a combined line carrier and radio organization.

Two methods of operation are available for direct transmission from a remote line carrier station through a radio terminal station to a distant radio station.

According to the first method, the'signal modulated waves. received from the line channels are combined with carrier waves of other different frequencies for transmissionto a distant radio station and the incoming radio waves carry signal modulated waves corresponding to the channel frequencies of the line system. Thus the frequencies of the different radio waves will be dependent to some extent upon the frequencies used in the line system andhence the radio carrier frequencies will have to be chosen to provide the proper frequency spacing between the incoming and outgoing Waves used in the radio system.

I While this method is contemplated by the present invention it involves difiiculties whichare resolved'by the second method. These difiicultiesreside in the uneconomical use of the frequency spectrum unless a complicated spacing system'is chosen for the whole radio organization. 7

According to thesecond method, which is preferable, the modulated carrier waves-re ceived over the line are each stepped up or down' to the same frequency level,are then used to modulate the radio carrier waves of 'difierent frequencies, and the incoming radio waves of different frequencies carry ing signal modulated waves of a single frequency are transformed into carrier modulated waves corresponding tothefdifierent line channels frequencies over which they are transmitted. The frequency spacing between the radio waves is therefore definite ly fixed independently of the carrier frequencies used in the line systemandghence an economical use of the frequency spectrum is obtained. 1 I

Fig WW6 "The terminal apparatus illustrated in Fig. 7 I

5'is adapted to utilizethe second method referred to above. i

The line 25 is conjugately connectedat to the circuits TC and BC. The fundamen tal frequencytransmitted over the line 25 is supplied through a selective device .81to a harmonic generator 82. The output. 'circuit of which includes'the necessaryselective means for the frequencies used in radio transmission. The circuitsTC and RC' are provided with means respectively 5 selective of the different waves used for communication over the line channels. I 1 1:

With reference to channel two, the signal wave of 10 KC+S received over'the line i is selected'by the filter. 83 and combinedin 182 to-produce a'modulated wave having a side component of 20 KG'(16%' KCI-SQ which is selected bythe filterv88. Theselect edcomponent, viz. 3 KC.S is impressed upon, the modulator 89 together with oscillations of KG transmitted from the generator 82 throughthe filter 90. The 1 side band of 123% KC'S is selectedby the fil ter 91, amplified byv the device92, which preferably includes means selective of the de sired side band, and radiated from the .antenna .93 to the distant radio station. A control frequency of 20 KC supplied by the generator 82 is selected bythe device 94 amplified by the apparatus 95 selected by the filter 96 and continuously radiated from the antenna 97. Incoming radio signal modulatediwave or side bands incoming into channel two. which is assumed to have a carrier frequency of 140 KC modulated by a wave of 3 KC-Sg, or 143 4), KCS is received by the antenna 98, selected and amplified, Iif -de-' sired, by the'device 99 and supplied to'the' I also. supplied to the detector 100, through the filter 101 and amplifier 102. The received waves'and local oscillations are combined in the detector 100 to produce a difference frequency wave of 23 KCS This wave is combined with oscillations of 6% KC in the modulator 103 amplified by the device 104 and the component of 30 KCf-SZ is selectively transmitted by the filter 105 through thecircuit BC. to the line 25. (Observe that channel 2 of Fig. 5 corresponds in frequencies and may be used interchangeably with channel 2 of Fig. 2 or 3).

The signal waves received over the fourth channel of the line 25, of frequency 16% KC-l-S are selected by the filter 106, amplified by the device 107, and combined in the modulator 108 with oscillations of 20 KC supplied by the harmonic producer 82 through the filter 94. i

The component 20 KC (16% KC-l-S or 3 KC S resulting from the combination of the incoming waves and the local oscillations, is selected by the filter 109 and combined in the modulator 110 with a carrier wave of 40 KC. The upper side frequency 10 KC+3 KC-S or 43% KC S, is selected by the filter 111, amplified by device 112, which preferably should include selectingmeans for the upper side frequency and supplied to the antenna 113 for radiation to adistant station.

The incoming radio wave forthe fourth channel, of KC carrier frequency modulated by awave of 3% KCS or 63% KC-"s incident upon the antenna 114 is selected, and if desired, amplified, in the apparatus 115 and supplied to the detector Oscillations of 40 KC derived from the generator 82, selected by the filter 117 and amplified by 118, are supplied to the detector 116. The resultant output wave components are amplified by the device 119 and the component of 23 KC-S which corresponds to that of the fourth line channel, is selected by the filter 120 and transmitted through the circuit RC, conjugate connection 80, and over the line 25 to the distant line terminal station.

A four channel organization is indicated, but obviously the number of channels may be increased to the maximum possible for the frequency rangeavailable. Each of the channels will be operated in a manner similar to that described abovefor channels two and four; i I

It is to be noted that all side bands radiated by, or received into the system of Fig. 5, are inverted and displaced relatively to the nearest carrier frequency which can be derived from the base frequency of 20 KC. Consequently these side bands cannot be received by means of a carrier wave which is a multiple of 20 KC'unless a component of 3% KC or one of the multiples thereof is also present.

It is to be understood that, wherever essential for. eflicient operation, the incoming and outgoing circuits of the different channels shown in Fig. 5, may include amplifying and selective means. This may be done by including the amplifying and selective devices in the different apparatus units shown, or by using separate units connected into the circuits.

In the organization shown in Fig. 5 a series of modulated waves, arriving over one series of channels having a fixed frequency spacing, are repeated as modulated waves of other frequencies over a second seriesof channels having a different but constant frequency spacing between them. This organization therefore provides for through repeating from one carrier system to a second carrier system, in which each system uses a series of waves of different frequencies uniformly spaced.

Inthis system a series of waves uniformly spaced apart and having one energy level may be transformed into a series of waves having a difi'erentuniform spacing and energy level, whereby carrier systems which are respectively efficient for short and long dlstance transmission or for low carrier wave and high carrier wave frequencies may be associated for joint operation.

A. complete system might comprise a channel extendingfrom line 26 (Fig. 2), through a channel of Fig. 2, line 25, a channel'of Fig. 5, and into a radio channel connecting with a similar system at the distant terminal. In no part of such a system between the low frequency lines would the signal waves be of the normal frequency of speech or capable of detection by a simple receiver.

Fig. 6 illustrates a radio station for use ina system having a terminal station adapted to transmit a carrier wave modulated by signal currents, the upper side frequency only bein radiated. A terminal station of this type is shown in Fig. 4.

Figures 6 and GA In Fig. 6, representinga ship station or other isolated radiostation, the antenna system including an antenna 121 is connected through a coupling circuit 122 and an artificial antenna. or balancing network 123 to ground. The coupling circuit 122 is tuned broadly to select the incoming and outgoing waves used at'this station and is c onjugately associated with the transmitting and re ceiving circuits. The receiving circuit is inductively coupled to the antenna system by the coils 12 1 and 125. A circuit extending from the midpoint of the coil 124 to ground and including the coil 126 is associated with the transmitting circuit by the inductive coupling between the coil 126 and the coil 127.

Fig. 6A illustrates an antenna. system and means for coupling the transmitting and receiving circuits of a radio station which is slightly different from that shown in the precedin figure. This arrangement may be substituted for that portion of Fig. ggvhich lies to the left of the section line In Fig. 6A the antenna system comprises the antenna 128 having two paths" to ground, one of which includes a'trap circuit 129 and a circuit tuned to the incoming waves 130. The second pathincludes a coil 131. The receiving apparatus is associated with the antenna system by the inductive coupling between the circuit 130 and the coil 125 and the coil- 131 is inductively associated with the coil 127 included in the transmitting circuit. The trap circuit 129 is resonant to the transmitted carrier frequency and is designed to permit a limited amount of energy of this frequency to be supplied from the antenna circuit to the receiving circuit, for a purpose to be described later. 1

According to the system shown in Fig. 6, the incoming signal wave incident upon the antenna 121 is transferred to the detector 132 through the coupling transformer 124- 125.

The radio control frequency of 20 KC incident upon the antenna 133 is supplied to the generator 134, adapted to produce 0scillations of different'frequencies harmonically related to the control frequency.

The generator 134 supplies oscillations of the desired frequencies for both transmission and reception.

In the example illustrated a component of 180 KC is selected by the filter 135 amplified by the device 136 and transmitted through the filter 137 to the modulator 138 to constitute the. carrier wave for outgoing messages. The device 138 may comprise any well known system for producing a. modulated high frequency-wave including, or having associated with it, means for suppressing the carrier component and oneside band component and for supplying the other side band component to the antenna. The device 193A whichmay be a telephone transmitter or other similar device for supplying modulating current to the device 138. Assuming that the frequency of the current supplied by the device 139 A is S and the lower side bandis used; the frequency of the transmitted radio wave will be 180 KCS The modulator may compriseapparatus' for wholly or partly sup pressing one side band and the carrier, or for radlatlng all the components of the modulated wave.

Let it be assumed that the corresponding The received waves and local oscillations are combined in the detector 132, to produce an intermediate frequencymodulated wave of 20 KC+S ,which is selectively amplified by the device 139. The'selected wave and local oscillations of 20 KC transmitted from the generator 134 through the filter 140 are suppliedto and combined in the detector 141 to yield the signalcurrent of frequency S which are impressed upon the receiving device 142, shown, by way of example as a telephone receiver.

Instead of supplying local oscillations for the first stage of detection through the filter V 135to the detector 132, the system may be designed to supply a certain amount of the outgoing energy of carrier frequency from the antennacircuit to the receiver circuit. This may be accomplished by providinga certain amount vof unbalance in the connection for coupling the transmitting and receiving circuits to the antenna circuit.

An arrangement for supplying the necessary energy of outgoing carrier frequency from' the antenna circuit to the input circuit of the first detector'is shown in Fig.

' The carrier wave of 180 KC is supplied through the coupling 127-131 to the antenna circuit, whence it is transmitted through the trap circuit-129 and circuit 130 to the coil 125 included in the input circuit of the detector 132. The incoming signal wave of 160 KC+$ incident upon the antenna will be transmitted through the trap circuit 129, circuit 130 to 'ground. Due to the coupling between coils 130 and 125 errer of the incomin wave of si al frequency 160 KC'l-S andthe outgoing wave of carrier frequency,'180 KC, traversing the antenna circuitwill be supplied to the input electrodes of the detector 132. The signal waves and local oscillations will becombined in. the detector to produce an inter=,

A characteristic feature of the invention is that ship stations .or other remote or isolated stations may communicate with each otheras well as the radio terminals associated withthe wire line systems. Any of the isolated stations may communicate with otherisolated stations not controlled as a part'of a systemin accordance with'the: invention provided'only that the other isolated stations are provided with wave sources of a suitable frequency or frequencies.

Figures '7 01ml 8 Figs. 7 and 8 illustrate a radio system adapted for use in a line carrier-radio organization. In this arrangement an unmodulated carrier wave, a modulated carrier wave, and a. wave of control frequency are radiated from a radio terminal station. In the receiving circuit at the distant radio station oscillations derived from the control wave are used to combine with the received modulated and unmodulated waves to provide the currents of different frequencies required for effecting successive detection of the incoming signal waves. At the terminal station the receiving arrangement includes a successive detection system which is supplied with combining oscillations derived from the wave of control frequency by a harmonic generator.

Figure '7 7 Referring to Fig. 7, there is shown a terminal station for multiplex radio operation.

A radio control wave of 20 KC is transmitted through a filter 144 from a line carrier system to a radio circuit including a transformer 145 and harmonic generator 146. The transformer supplies the control wave through an amplifier 147 and filter 148 to an antenna 149 from which it is continuously radiated. The output circuit of the generator 146 includes the necessary selective devices or filters for the different frequencies used for two-way radio communications over a number of channels. As stated above, a successive detection receiving system is used.

Since all of the channels utilize the same principles, it is believed that the functions of the different elements constituting the radio terminal apparatus will be clear from the following description of the operation of one channel. The frequencies used in the several channels will, of course, be different.

Low frequency currents, for example speech currents, are transmitted over the line 150 which is conjugately connected through the circuits RC and TC to the radio apparatus.

The low frequency energy received from a distant station over the line 150 is amplified by the device 151 and supplied to a modulator 152. A carrier wave of 20 KC is also supplied to the modulator. The low frequency current and carrier wave are combined to produce a carrier modulated wave the upper side band of which, or 20 KG-l- S is selectively transmitted through the filter 153 to a modulator 154 to which the generator 146 supplies a carrier wave of 1,000 KC through the filter 155. The modulated carrier wave of 1,020 KC+S resulting from the operation of the device 154, is selected by the filter 156, amplified by 157, and radiated from the antenna 158.

The harmonic generator 146 supplies a wave of 1,020 KC through the selective means 159 to an antenna 160 from which it is radiated.

Incoming carrier signal modulated waves of say 1,040 KC-S incident upon the antenna 161 at this station are combined with oscillations of 1,000 KC, supplied by the generator146, in the detector 162. The side component of 40 KCS, thereby produced, is transmitted through the filter 163, amplified by the device 164 and combined in the detector 165 with oscillations of 40 KC supplied by the generator 146 to yield the low frequency signal currents. The filter 166 selects the low frequency currents which are then amplified by the device 167 and transmitted over the circuit TC and line 150 to the subscriber.

F igure 8 As shown in Fig. 8, which may represent the circuit of a ship station or other isolated radio station, the incoming control wave of 20 KC incident upon the antenna 168 is transmitted by the selective means 169 to a harmonic generator 170 and also to a mod ulator 171. The generator 170 supplies com;- ponents harmonically related to the control frequency through selective devices 172 and 173 respectively, to a modulator 174 and a detector 175.

In this system, the incoming unmodulated carrier waves of 1,020 KC, the modulated carrier of 1,020 KC+S, and 1,040 KC are supplied to the detector 175 in which they are combined. The components of 20 KC-i-S, and 20 KC resulting from combining the two incoming waves with the 1,040 KC oscillations supplied by the generator are selected and amplified by the device 176. The amplified energy is supplied to and combined in the detector 177 to yield the low frequency signal current which is used to actuate the receiver 178, herein shown as a telephone receiver.

Signaling currents are supplied by the device 179, for example a telephone transmitter, to the modulator 171 wherein they are combined with a wave of 20 KC received from the selective device 169.

The lower side frequency component, or 20 KCS is selected by the filter 180 and transmitted to the modulator 174, in which it is combined with a high frequency Wave of 1,020 KC supplied by the generator 170 through the filter 172. The resultant lower side frequency component of 1,040 KCa-S is selected by the filter 181, transmitted to the antenna 181A and radiated to a distant station.

This may be a terminal station,

similar tothat shown remote station.'. i 1 n v r In the circuits of Figs. 7 and 8, it is to be understood that separate/amplifiers maybe used wherever they are necessary to eflicient operation, I

. 1' FigureQ in Fig. 7, or any other Fi 9 illustr'ates a line carrier and radio combination involving the invention, which may be used for broadcasting or transmitting for other purposes simultaneously from zeroi r r r At the -localiradio station the 'modulated ,ulator 191. 1

Widely separated radio stations on the same wavelength; I, V

, In Fig. Qthere are shown two radio broadcasting stations,for example one at Chicago and the other at New York connected I carrier line. Additional circuits are'fconnectedto the carrier line toindicate that the connection may be extended to any numtions. r 1

Let it be assumed that the studio is situated-at Chicago. The message or entertainment tobe broadcasted is supplied by the transmitter 181' to amo'dulator 182, also supplied with a carrier wave vby a harmonic generator 183,through a filter 184; A source. 12 which may be the mast'e'r oscillator'indi cated in Fig, 2 0I another source, if desired,

supplies the fundamental frequency to the harmonic generator 183. The fundamental frequency, as in the systems previously 'described, may be 3 KC and istransmitted through the filt'e'r 186 to the device 187,

which supplies amplified energy. of frequency to the carrier line 188.'

A carrier wave of .30'KC'iistransmitted the :base

through the filter 184 to the modulator 182' where it is'com'b ined' with the message currents of,,.for example, frequency received from the transmitter 181, to producea modulated carrier wave. The upper side fre'- quency of 30 KC+S is selected by thefilter 189 and transmitted simultaneously to the local radio broadcasting station, and after being-amplified by'the device 187, over the] line 188 'to the distant station or stations.

The channel 30 KC+S is assumed to be a high quality channel suchas will transmit the entire range of frequencies involved by varying 'S over a'range of 5,000 'cycles to Wave 30 KC-l-S'is transmitted through'the filter 190' tothem'odulator;191*. The filter 190 serves to transmit the 30 KC+S wave substantially without attenuation andto pre-' vent the flow of the fundamentalfrequency to the modulator 191. A carrier wave of "803 /3 KC, produced by the'generator'183, is

transmitted through a filter 192, amplified by'the device 193 and supplied to the mod- The modulated'wave of 30KC+ S and the wave of-803 KG-are combined in the modulator. Theriupper side band of KC-l-S, .andnthe unmodulated carrier of 833%. -KC are transmitted through the filter 194 to thQ-flIltBDIlfi; 195; I

At the New York station the fundamental frequencyselected by the filter 1196 is supplied to a harmonic generatoradapted to supply a component of v803 A; KC to a modulator 197410 whichnthe'modulatedwave of 30KG+ S, incoming over line 188,:is selected by the filter 198.

I The modulatedwave'ofBOKC+S andithel y l component of 833%;KG are combined in the:

modulator-197., the upper side frequency of 833 /3 -KCrtS, and ,unmodulated carrier of: 803 are transmitted'through the -filter-199 and radiated from the antenna 200.

r The modulated line carrier wave. 30 KC+ l S, and a wave of the fundamental frequency 3 KG may be transmitted. over other lines,

may be any number,to similar radio broad-- casting stations.

The studio may be situated at stations and by using a plurality of channels,

associated with the lines" different messages or entertainmentsoriglnatmg at one or more of thestations may be broadcasted from one f f I or more stations of the system. Moreover,-

the channel described abovemay be one of a multiplex carrier system, such asthatof Fig. 2', in which the other channels are used to carry commercial trafiic. i v e :ith the system just described, the

cast program may be radiated from a plur rality of stations'situated at'geographical or broad-i i commercial centers of acountry or continent on a wave length which is absolutely the same, the emission, except'for the short in listener at an intermediate point, itis im-' material whether the energy received by himv is derived from one or more or an of the: radiating stations.- 'It will be observed that the frequency of 833%, KCcorresponds to the, 360 meter wave length widely used in "broadcasting and other wavelengths differing bypunits of 3 6 10 or13 may readily: be used; 7 V

v FigWes5'and 10 Referring now. to Fig. there is shown,

in dottedrline, a channel for extending the system to distant geographical entities for example to the other-continents or islands or systems onthe same continent not connected by. wire lines. v p I V The filter 210 selects a carrier-wave of I say 200 KC and transmits it to a modulator 211 which is also supplied with energy of;

the base frequency, 3 KG. The carrier 1 and base frequency waves are combined in the modulator 211 to produce a modulated wave of 200 KCi3 KC which, together with the unmochilated carrierv wave compo nent of 200 KC is supplied to and amplified by the device 212. Theeamplified modulated and unmodulated components are supplied to and radiated from the antenna 213.

I At"a distant island or continent a radio receiving system similar to that wshownin Fig. ,10 used; The incoming modulated- 1 side band components and theunmodulated carriercomponent incident uponthe antenna 214 are supplied to and combined in the detector '215'to yield the wave'of base frequency 3% KG, which is selected and amplified by the device. 216. The amplified wave. of base frequency" I is transmittedthrough a selective device or filter 217 and a line 218 to a harmonic generator 13 includedin a terminal cont'rolstat1on s1m1lar to that shown'inl ig. 2. I I

'By duplicating the arrangements. hereinheforedescnibed and combining them to supply linecarrier and radio systems, a

' carrier. signaling: organization having the 3Q desired characteristic maybe provided for I a second geographical entity, the frequen- V at as constant a frequency as possible.

cies used in the difierent systems of this sec-,

ond organizationwill be determined bythe generator 13 atstation 1 of Fig. 1.- In like -manner, carrier organizations for several different entities and in fact for any number of systems on the same or diiferentcontinents may be interconnected to constitute a universal combination having all the fre-.

- via. station 3 or station 4. Furthermore it is contemplated that any carrier system be. coming disconnected by accident or otherwise from the master oscillator source 12 may by a simple emergency arrangement of; a radio. receiver such as that of Fig. receive the standard frequency wave of 3 KG if such mode of operationis deemed desirableand if such apparatus as the dotted line portion of Fig. 5 is functioning;

The standard KG; radio frequency is 'quency. c

of held in absolute synchronism.

radiated from as many separate points and with, such, power as may benecessary to keep all radio stationssupplled with sufficient frequency setting energy of the desired fres This inventi ganization in which i may be included any number of linecarriersystems, each having one or more channels, and any number of radio systems, each having one or more; chair on contemplates a carrier or-v nels whethenadapted' for independent op eration or cooperatively associated and having the frequencies used in .the different systems as Well as each of the channels there- The principles of the invention are 1-H;

dependent of. the type of apparatususedw g in thevarious systems, i. eamplifiers, modu-- 'lators or 'inodulating apparatus, selective,

devices, and sources of carrier waves or Sig 'nal currents/Moreover, each system may utilize the well known principles, of operation peculiar to. their respective types, vwhether used for. telegraph, telephone or other. signaltransmissions', or for control purposes." M. 'l/Vlnleseveral chfierent arrangements have beendescribed for the purpose of clearly and completely j disclosing the nature of the invention, it is; to beunderstood that. this invention: may be embodied in many different' modificationszwithout departing'from 7 its princip.les, and hence I that is not to, be, limited to thespecific, features and arrange-Y ments described but only by the scope of the attached claims. k i

What isclaimedis:

.1. In a communicating arrangement embodyingline carrier systems and one or more radio systems, the method of operating the arrangement which comprises supplying a wave of given frequency, controlling the frequencies of the carrier waves for the line systems and a radio control wave by said. wave of givenfrequency, and con trolling the frequencies of the radio carrier wavesby said wave of radio, control frequency.

2. In a; communicating. arrangement a.

line carrier system and; a radio system cooperatively associated, means for supplying a wave of given frequency to said arrangement, meanslfor controlling bysaid wave of given frequency the. frequencies of the carrier waves for. said linesystem and a control wave for said; radioisystem, and means for controlling 'by said controlwave thefare.

quencies of; the carrier wayesfor said; radio system. i

, 3. In acommunicatingarrangement a line carrier system and, a radio system coropers atiyely associated, means "fbr supplying .a wave of given frequency to saidjarrangement, means for controlling by said wave of given frequencytthe frequ cies of the carrier wavesfor saidline; system and oontrolrw'ave. for 831d. radio system, and

means for controlling by said control wave the frequencies of the-waves used .for transmissionand the oscillations used for suc-. cesslve (16t8Ct1OI1IeC81V1I1g systems included in saidradio system.

4. The method which comprises fixing and maintaining line wire channels of a plural channel signaling system with agiven fre-.

quency SGPiLI'ZLlSlOIl and maintaining one or more sets of radio channels with a frequency separation .Which is an exact multiple. of that used for the line Wire channels.

5. The method of controlling signaling Wave frequencies which comprises maintainingrcarrier'line channelsovera given region spaced bya constant amount and maintain by a constant multiple thereof. A

6; The method of radio transmission which ,comprises supplying to. .a. plurality of'stations a wave of given frequency to controlat each station the'production of: a radio carrier Wave of single-frequency,

modulating the carrier waves by the same; message, and radiating the modulated waves..-

' 7 A radio system comprising a plurality of transmitting stations, means for 'supply-. ing to said stations a wave of given frequency for controlling at each of said sta-.

tions. the production of a radio carrier'wave of the same frequency, and means atea'ch station for modulating. said radio ave by 'I the same :message and for radiating said modulated waves.

, 8. A line-wire-carrier and radio organization having. a fixed. spacing of carrier channels,- andmeans whereby waves of frequencies-Which are'multiples: of the spacing'frequency value are employed as lineradio translating waves at llne-ra-dio unctionpoints. I

9. In "combination,ia plurality of radio transmitting stations, means individual to eachjof-the stationsfor applying signal,

variations to the wave transmitted-therefrom,-and means, including a generator of low-frequency oscillations, for maintaining a' definite frequency relation between the carrier'waves transmitted from said stations! In combination, a plurality of radio transmitting stations separated geographioally a distance independent of the radiated wave length, a control-frequencychannel linking said stations,and means associated with said control channel for. gener ating low-frequency oscillations.v

11.. In combination, a plurality of, radio transmitting stations,"a control frequency channel linking said stations, means for generating a control-frequency, means at each station for deriving a radiation frequency from said control frequency and meansfor ing-radio channels over theregion spaced frequency Wave.

supplying to each station. a modulation nee quency from a common source.

..12.-.ln combination, a pluralityoff'radio transmitting stations, a control-frequency channel linking said stations, means forgeflera-ting a control-frequency associated. with. said .controlrfrequency, 1 channel, means for, impressing audio-frequency potentials. on said channel, means at certain of} said; sta' tions for deriving a high frequency@fromv saidcontrol frequency, and ,meansywhereby said audio-frequency? may. :be employedto modulate said high frequency.- .I i g I." at. 13. In combination, a plurality of, transmitting stations each operating at a different frequency, certain of said stations comprising means for deriving a high-frequency oscillating current fromv a audiblerfrequency control-current, means for generating, I and supplying to certain of saidstations it 01 5? ro1- rre d means a ce ainl-Qfi id;

stations for amplifying the said derived. high frequency; V A I I .14. A radio itansmission comprising a; master control station: and a 1 plurality of; radio transmitting stations,1 .means; at {the control station for generating ,a; line; wire; carrier Wave, means comprising. line 1 {wires for; transmittingj' the carrier wave 'to each radio transmitting. station, means at ;-each of the radio. transmitting istationsffor in.-;

creasing to the same degree. the-frequency;

at; the. control stationfor generating a line 7 Wire carrier wavedmeans; comprising line wires for transmitting. the'carrier Waveito each radiotransmitting station, distortion means at each of the radio transmitting sta-v tions 5 for producing harmonics of the line carrier- Wave, .means at 'each of the radio transmitting stations for increasing the frequencyziof said' wave to th'e same degree toproduce at-each station radio carrier.

its

wave-of comparatively. high frequency-gel atively to that of? theline carriervwave :by filtering out. a desired harmonic. of the :line

carrier .wave,.meansf at .thefmaster control i station for generating awave nofasignal frequency, =means" comprising line wires :for transmitting. the signal frequency "wave. to each radio transmitting station, ,andnieans. at each radio transmitting- .station for. mode ulating the radio carrier wave by the signal frequency wave. r a i a l 1-6; In comb'nation, a plurality of-radio transmitting stations a control frequency channel linking said stations, means for generating a control frequency associated with said control frequency channel, means for;

at a master control station, transmitting the,

carrier wave over line Wires to a plurality of radio transmitting station's, changing the frequency of theline wire carrier Wave to the same degree at each of the transmitting stations to produce at each station a radio carrier wave of frequency high relatively to that of the line wire carrier wave, and modulating the radio carrier wave at each radio-transmitting station by a Wave varying in accordance with signals said master control station. a i i i 18. The method of radio transmission which comprises generating at a master control station a carrier wave of such frequency that a given harmonic of said wave will be of a desired radio frequency, transmitting the carrier wave over line wires to a plurazlity of radio transmitting stations, distor-ting the wave at each transmitting station to produce harmonics of said "wave, in-

creasing: the frequency of the carrier "Wave to: the same degree at each of the transmit ting stations to produce at each'station a radio carrier Wave of frequency comparatively high relatively to that of'the line car rier wave by filtering out the desired har-:

monic of the line wire carrier wave, and modulatlng the radio carrler wave at each radio-transmitting stationcby a wave vary ing in accordance with signals generated at said master control station. a I

r 19". A radio transmission system comprisinga master: control station and a'plurality of radio transmitting stations, means at the master control-station for generating a line,

carrier wave, means comprising line wires for transmitting the carrier wave to each radio-transmitting: station, means at each of'theradio transmitting stations for in-. creasing to t-he same degree the frequency of the line wire'carrier wave to produce at eachstation: a radiocarrier wave of comparatlve lyhigh frequency relatively to that oflthe line car'rierwave, means at the master control station for generating a. wave varying in accordance with signals, means comprising line wires for transmitting the signal variations to each radiotransmitting stagcnera-ted at tion, and means at each radio transmitting station for modulating the radio carrier wave by the signal variations. 7 20. A radlo transmission system comprising a master control statio n and a plurality of radio transmitting stations, means at the control station for generating a line wire carrier wave, means comprising line wires for transmitting the carrier wave to each radio transmitting station, distorting means at each of the radio transmitting stations for producing harmonics of the line carrier wave, means at each of the radio transmit ting stations for increasing the frequency of said wave to the same degree to produce at each station a radio carrier wave of comparatively high frequency relatively to that of the line carrier wave by filtering out a desired harmonic of the linecarrier Wave, means at the master controlstation for generatinga Wave varying in accordance with signals, means comprising line wires for transmitting signal variations to each radio transmitting station, and means at each radio transmitting station for modulating the radio carrier wave "by the signal varia-h tions. a v, i r t 21. In a communication network including a number of radio receiving stations, means to transmit by radio to said stations side. band components of signal modulated waves without the unmodulatedcarrier component, means tosu-pply continuous waves :to said stations by wire from a common point, and means at said radio receiving stations for combining with the side band components received by radio, waves derived fromsaid continuous waves to receive the signal.

22. The method of secret signaling which comprises controlling the action of signal transmitting apparatus a so as to produce two complementary components of a signal modulated wave, both of which are essential to intelligible reception of the signal, broadcasting one component and separately supplying the other component by point-to-point transmission to those receiving stations, in the field of said broadcast component, with which it is desired to communicate.

23. The method of Wide area broadcasting which comprises generating, variations corresponding to the signals to be broadcast, conveying said signal variations by wire to a plurality of broadcasting radio transmitting stations, impressing. said signal variations upon radio frequency currents produced at each of saidstations, and radiating simultaneously from each said station, electromagnetic waves having'a common single carrier frequency and modulated in common by said signalvariations. a

24. A radio transmission system comprisinga master control station and a plurality of radio transmitting stations, means at the control station for generating a line wire 

